Use of a manganese, zinc and/or cobalt salt in a two-steps dyeing process based on an ondole or indoline compound

摘要

Use of Mn, Zn and/or Co salts in a one-step process for dyeing keratinic fibres (esp. human hair) using an indole cpd., in order to obtain light grey shades that do not change with time, is new. The salts are acetates, halides, sulphates or carbonates, esp. Mn(OAc)2.4H2O or ZnCl2, and are dissolved or dispersed in a compsn. contg. the indole cpd., pref. to give a metal concn. of 0.001-4 (esp. 0.005-2) wt.%. The indole cpd. is esp. 5,6-dihydroxyindoles (Ia) but could also be another cpd. of formula (I): R1-R4 = H or 1-4C alkyl, provided that R1-R3 = H when R4 = alkyl.